Typically decorative boxes such as candy boxes are made of a paper board material and are covered with decorative paper. They comprise a box body having a side element and a closure at the bottom, and a cover with a side element and a closure at the top. The sides are formed with bends, corners and the closures conform to the shape of the sides. Covers may be fully removable or hinged in some manner such as by a paper hinge. Boxes vary in durability and purpose; the strength of the materials and the construction method used varies depending on the desired durability and purpose. To form corners, the structural element may be scored and bent to define a sharp corner. To form curves the structural element is bent into a curve of the desired shape without exceeding the bending strength of the material. Usually the ends of a continuous side element will meet at a place where there is to be a corner or sharp turn in the shape.
A particular field of boxes is candy boxes. These are made to survive the journey to the customer (subject to careful handling) with their decorative features intact and from then only need to last a short time until the candy is consumed. The particular materials and ruggedness of construction required for candy boxes is well known in the field. An especially popular type of candy box is the heart shaped box used in great quantities for the Valentines Day holiday.
Cost is an important factor which is manifest in both the material cost and the labor cost including the adaptation of automation to make the boxes.
Typically the structural elements will be glued together; although it is possible to join the elements by means of a decorative paper cover extending from one structural element to the other. Sometimes both means are used, together.
In a large box of this type, greater strength is needed in joining the structural elements such as the side element and the bottom closure. Also, some boxes shapes have portions of the side element bent inwardly convexly or concavely to form a shape. This bending inwardly creates a tendency to straighten, that is to unbend. Therefore there is a need to have a construction and method, which will strongly hold all the parts together against the tendency to straighten.
One solution to this problem is seen in U.S. Pat. No. 5,400,917. In that patent there is disclosed a three layer bottom closure assembly for the bottom of the box, which can also be used for the box cover. The exterior layer of the three layers is made of lightweight board suitable for the desired appearance and strength of the box. The interior layer is also made of lightweight board. The glue problem is to provide enough area of contact of a glue bead between the side member and the two layers that comprise interior and exterior layers. By inserting a spacer between the exterior layer and the interior layer, the spacer being slightly smaller or scalloped around its edges a space or channel to receive glue is provided. This provides for an extended area of glue contact on the side member due to the thickness of the spacer and also an extended area of glue contact with the inner and outer members due to the space created by the reduced size or scalloping of the spacer.
It would be of considerable benefit if the requisite glue contact could be accomplished consistently over large volumes of box manufacture without the enlargement and extra cost (both materials and labor) caused by the spacer. The present invention provides a solution to the problem of strong glue contact without use of a spacer and allows automation for high volume production.